Circular knitting machine takeup with a slitting device

ABSTRACT

An apparatus for progressively longitudinally slitting a tubular knitted fabric on a knitting machine as the fabric is progressively knitted during the operation of the machine prior to being wound up into a roll thereon so as to produce a wound up strip of knitted fabric folded lengthwise upon itself.

nited States Patent [191 Lee [ Dec. 24, 1974 22 Filed:

[75] Inventor: Billy M. Lee, Greensboro, NC.

[73] Assignee: Burlington Industries, Inc.,

Greensboro, NC.

Mar. 24, 1972 [21] Appl. No.: 237,685

[52] US. Cl. 66/147, 66/151 [51] Int. Cl D04b 35/00 [58] Field of Search 66/147, 151; 26/55 WC [56] References Cited UNITED STATES PATENTS 770,633 9/1904 Folsom 66/147 790,770 5/1905 Wildmanm. 66/147 1,298,006 3/1919 Chatfield 26/55 C 3,472,048 10/1969 Shaw et a]. 66/147 3,714,800 2/1973 Mazzi 3,768,279 10/1973 Butler 66/147 FOREIGN PATENTS OR APPLICATIONS 1,236,311 6/1960 France 66/147 1,061,189 3/1967 Great Britain 26/55 C OTHER PUBLICATIONS Orizio advertisement in Knitting Times, 40(6), p. 63, Feb. 8, 1971.

Wevenit advertisement in Knitting Times, 42(31), p. 17, July 23, 1973.

[57] ABSTRACT An apparatus for progressively longitudinally slitting a tubular knitted fabric on a knitting machine as the fabric is progressively knitted during the operation of the machine prior to being wound up into a roll thereon so as to produce a wound up strip of knitted fabric folded lengthwise upon itself.

7 Claims, 4 Drawing Figures CIRCULAR KNITTING MACHINE TAKEUP WITH A SLI'ITING DEVICE This invention relates to the knitting of tubular fabric and more particularly to improvements in the method and apparatus for producing graded rolls of knitted fabric in open width strip form.

The invention is particularly concerned with the type of fabric produced on conventional circular knitting machines, the operation of which produces a double knittubular fabric having a circumference of the order of 60 to 64 inches. A tubular knit fabric of this size has very limited use in fabricating garments or other articles in its tubular form. Almost the entire production of fabric of this size is used in fabricating garments and other articles in an open width form. The use of open width double knit fabric in garments has become quite prevalent in recent years and the popularity and demand for goods of this type is still increasing. The practices heretofore carried out in producing open width double knit fabric involve the initial production of the double knit fabric in tubular form on'circular knitting machines. In the normal operation of such machines, the tubular double knit fabric is progressively formed by knitting yarns to one end thereof, while the tubular fabric is rotated about its axis. The tubular fabric which is progressively formed is conventionally passed longitudinally over a spreader structure which flattens the tube. From the spreader structure, the flattened tube is fed between cooperating take-up rolls and the flattened fabric is finally wound up into a roll. The spreader structure, take-up rolls and roll spindle are all mounted on the machine to rotate about the axis of the tube being knitted during the operation of the machine.

In the production of open width double knit fabrics, the practices subsequent to the formation of the flattened tubular rolls on'the knitting machines have varied depending upon the type of processing equipment employed. In general, the processing equipment is operable either to process double knit material while in a tubular form or while in an open width form. Where the processing equipment handles the double knit fabric while in a tubular. form, the slitting operation must be performed subsequentto the processing operation and hence the present invention has no applicability. On the other hand, where the processing equipment operates with the fabric in open width form, a slitting operation must be performed prior to the processing of the fabric and the present invention can be applied to great advantage. Heretofore, the slitting operation has been performed either at the knitting mill or at the processing plant just prior to processing. Where the slitting operation was performed at the knitting mill, the prior practice was to first inspect and grade the flattened tubular rolls of fabric produced on the knitting machines prior to slitting, the slitting operation being performed on a separate machine.

The procedure of simply providing a longitudinal cut in an elongated tubular double knit fabric when viewed as an isolated operation, seems quite simple. However, the machines heretofore provided for accomplishing this simple function have been fairly large and quite costly due to the necessity of providing for means to handle the rolls of flattened tubular fabric and to present the tubular fabric to the cutter in a controlled manner so that a straight cut is insured. Such machines provide additional means for rolling up the slitted fabric preferably after the same had been opened or unfolded. Experience has shown that not only are the available slitting machines costly in terms of capital investment, but they require at least one operator and sometimes two, whether utilized at the knitting mill or at the processing plant. Moreover, the construction and operation of these machines was also made complicated in order to provide the capability of being able to form the slit in any desired location within the tubular fabric. This capability was regarded as an important advantage in the'sequential inspecting-slitting procedure of producing knitted fabric. Thus, by inspecting and grading the roll of flattened tubular fabric produced on the knitting machine prior to the slitting operation, a fault in the fabric which extended longitudinally for a considerable length could be noted so that when the slitting operation was subsequently performed, the slit would be formed coincidental with the noted fault. In this way fabric need not be downgraded.

The present invention is based upon the fundamental principal that significant advantages can be achieved by effecting the slitting operation on the knitting machine and that these advantages greatly outweigh the disadvantage of not being able to form the slit along a previously noted fault. v

A significant advantage of the present invention resides in the formation of a more accurate cut or slit than can be formed by the procedures heretofore practiced. In prior procedures, the roll of flattened tubular fabric from the knitting machine is first run through an inspecting machine where it is unwound and wound up again at least once and sometimes twice. Any such han dling of the fabric has a tendency to cause local lateral displacements therein. Moreover, after the inspection procedure, the fabric then must be processed through the slitting machine requiring the roll to again be unwound and passed through the slitting mechanism.

Even assuming that all of the previous handling of the foldedroll has not introduced any local lateral displacement in the fabric, the passage of the fabric through the slitting mechanism presents problems of lateral control of the fabric which make the formation of a straight slit or cut quite difficult if not impossible to obtain. In order to maintain any lateral control of the fabric during the slitting operation, it is necessary to provide structure which contacts the interior of the fabric. This interior control structure obviously must extend laterally through the slit and, to be most effective, must extend longitudinally upstream of the longitudinal movement of the fabric. Moreover, a downstream pull on the fabric must be applied in order to accomplish the longitudinal movement of the fabric over the interior control structure and through the slitting mechanism. Consequently, proper lateral alignment is dependent upon applying a uniform pull to a slitted fabric. The problems of maintaining lateral alignment through a pull on a slitted fabric are magnified where the slitting machine functions to open the slitted fabric (a desirable operation to minimize crease time) and to roll it up in open condition. These problems of lateral control are obviated by the present invention since the slitting operation is performed at a time when lateral control is assured by the knitting procedure itself and interior access to the fabric is readily available through the open end of the tubular fabric as it is being formed. Moreover, greater accuracy can be obtained because slitting can be accomplished at relatively slower longitudinal speeds in comparison to conventional slitting machines (e.g., a conventional slitting machine usually has a speed capacity sufficient to handle the production from as many as 36 knitting machines).

Uneven slitting is not only deleterious to fabric quality but presents serious difficulties in the subsequent processing of the fabric in open width form, due to the unstable condition of the edges formed in the slitting operation. These difficulties are magnified where the slitting operation is performed at the position in the fabric where the same has been folded for some time as is usually the case, except where slitted on a longitudinal fault. The problem of edge stability is sufficiently severe that it is frequently the case that a selvage section is knitted into the fabric for the express purpose of receiving the slit. Of course, where this practice is utilized, the advantage of slitting on a longitudinal fault is lost completely.

Another advantage of the present invention is that it greatly facilitates subsequent processing and particularly the procedures heretofore required to produce open width knitted fabric. When used in conjunction with the procedures and equipment disclosed in commonly-assigned application Ser. No. 237,753 filed concurrently herewith, in the name of Lyle G. Estes, the formation of permanent fabric creases is substantially eliminated and savings in both capital investment and operating costs can be obtained.

Accordingly, it is an object of the present invention to provide a method of slitting tubular knitted fabric which obtains the advantages set forth above.

Still another object of the present invention is the provision of an improved apparatus for a knitting machine which renders the knitting machine capable of producing rolls of slitted tubular fabric folded lengthwise upon itself.

IN THE DRAWINGS:

FIG. 1 is a schematic perspective view, with parts broken away for purposes of clearer illustration, of a double knit circular knitting machine embodying improvements constructed in accordance with the principles of the present invention;

FIG. 2 is an enlarged fragmentary sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a fragmentary view taken along the line 3-3 of FIG. 2; and

FIG. 4 is a side elevational view of the structure shown in FIGS. 2 and 3 illustrating a driving mechanism of modified form.

Referring now more particularly to the drawings. there is shown in FIG. 1 a knitting machine, generally indicated at 10, modified in accordance with the principles of the present invention. The knitting machine illustrated in FIG. 1 is a conventional double knit circular knitting machine manufactured by France Morat GmbI-I and marketed under the registered trademark MORATRONIK Model St-4. It will be understood that the principles of the present invention may be applied to any of the known double knit circular knitting machines, examples of which include the Mayor Ilgor I800, the Mayer Ilgor 1680, the Mayer OUJA, the Stibbe Mini-lac, etc.

The present invention is more particularly concerned with modifications or an improvement in circular knitting machines of this type, such improvement preferably being in the form of a slitting mechanism attachment, generally indicated at 12. As shown in FIG. I, the attachment I2 is mounted in cooperating relation with certain component elements of the conventional knitting machine 10 and hence the present application will be concerned with a description of the machine 10 only to the extent necessary to obtain an understanding of the installation and operation of the attachment 12 in conjunction with the machine 10.

The machine 10 includes the usual needle cylinder 14 which is mounted for rotation about a vertical axis.

During the rotation of the needle cylinder, the yarn which is fed thereto is progressively knitted to one end of a length of tubular fabric which extends downwardly from the needle cylinder. A spreader structure, which is mounted for rotational movement in synchronism with the needle cylinder 14, extends downwardly into the interior of the tubular fabric and is shaped to engage the interior of the tubular fabric so as to apply a predeten'nined transverse of lateral tension thereto. As shown, the spreader structure serves to deform the tubular material from the cylindrical configuration conforming to the needle cylinder into an elongated flattened configuration. In this regard, it will be noted that the spreader structure includes a pair of lower horizontally spaced downwardly tapering portions, one of which is illustrated at 16 in FIGS. 2 and 3.

Mounted below the'spreader structure 16 is a carriage structure 18 which is rotated in synchronism with the needle cylinder. The carriage structure 18 has a pair of take-up rolls 20 journaled thereon. The take-up rolls 20 are mounted on the carriage structure 18 for rotation about parallel horizontally spaced axes in a position to receive therebetween the flattened tubular fabric as it passes downwardly from the lower end portions 16 of the spreader structure. In accordance with usual practice, the take-up rolls 20 are driven about their axes in timed relationwith the rotation of the carriage structure 18 about its vertical axis so as to apply a predetermined longitudinal tension to the tubular fabric as it is progressively knitted during the operation of the machine. The fabric passing through the cooperating take-up rolls 20 extends under the periphery of one of the take-up rolls and then over the periphery of a cooperating third take-up roll 22 which is likewise driven in synchronism with the take-up rolls 20 and journaled on the rotatable carriage about a parallel horizontal axis. From the take-up roll 22, the flattened fabric extends downwardly to a roll forming mechanism, of conventional construction, indicated at 24 in FIG. 1, which mechanism is also mounted on the carriage structure 18 for rotation therewith. The roll forming mechanism 24 is operable to wind up the flattened fabric into a roll on a tube or the like in accordance with conventional practice.

Referring now more particularly to FIGS. 2 and 3, the slitting attachment 12 comprises in general a rotary cutting blade 26, a rotary drive transmission assembly 28, a driving mechanism and a mounting arm assembly 32.

While the drive transmission assembly 28 may be of any desirable construction, the preferred embodiment shown includes a generally L-shaped tubular housing 34 open at opposite ends. Threadedly engaged within one end of the housing 38 is a sleeve 36 carrying a bearing 38 on the interior periphery thereof within which a cutting blade shaft 40 is journaled.

Asbest shown in FIG. 2, the shaft 40 extends outwardly of the housing and the rotary cutting blade 26 is fixedly attached to the outwardly extending end of the shaft, as by a conventional threaded coupling assembly 42. Threadedly engaged within the opposite end of the housing 34 is a sleeve 44, similar to the sleeve 36, having a bearing 46 mounted on the interior periphery thereof. Journaled within the bearing 46 is a drive shaft 48. Disposed within the housing 34 is a pair of meshing bevel gears 50 and 52 fixed respectively to the inner ends of the shafts 48 and 40.

' The drive shaft 48 extends outwardly of the housing 34 and is connected with the driving mechanism 30. As will become more apparent hereinafter, the drive mechanism 30 may assume several different forms, however, as shown in FIG. 2 the mechanism consists of a pulley 54 suitably fixed to the outer end of the drive shaft 48 by any appropriate means, asfor example, a

bolt 56 or the like. Bonded to the exterior periphery of the pulley 54 is a sleeve 58 of resilient material'such as a rubber or the like The mounting arm assembly 32 may likewise be of tion of the periphery of the cutting blade may be protected as by an arcuate guard 82 suitably fixed to the collar 60, as by a mounting arm 84 or the like.

The construction of the slitting attachment 12 with the driving mechanism 30 as described above is preferred because of the simplicity of construction and ease of installation. The drive mechanism 30 is limited, however, in the maximum rotational blade speed that can be achieved, utilizing a l to 1 gear transmission assembly. With the arrangement shown, since the sleeve 58 has a circumference slightly greater than the circumference of the take-up roll 22 which drives the same, the rotational speed of the drive pulley is somewhat less than the rotational speed of the take-up roll 22. Since the cutting blade is generally equal to the size of the pulley sleeve combination and the drive transmission is a l to 1 gear ratio, the cutting speed of the blade will be generally equal to or slightly less than the linear speed of fabric movement thereby. When operating at such relatively slow speeds, it is specifically preferable that the direction of rotation of the cutting blade be such that the portion of the blade engaging the fabric moves in a direction generally opposed to the direction of fabric movement, which would be in a counterclockwise direction, as viewed in FIG. 3, for the blade 26. Indeed, this direction of movement of the cutting blade is generally preferred, although a cutting blade movement generally in the same direction as fabric any suitable construction. The preferred embodiment shown in FIG. 2 includes a collar 60 of a size to engage over'the housing 34. The collar is fixed to the housing by any suitable means, such as a set screw 61 or the like. Fixedly secured to the periphery of the collar is one'end of an arm 62, the opposite end of which is fixedly secured to a sleeve 64. The sleeve is mounted over one end portion of a rod 66 which permits adjustment both rotationally and longitudinally. The sleeve 64 is fixed into an appropriately adjusted position with respect to the rod by any suitable means such as set screws 68 or the like. The opposite end of the rod 66 has a bracket plate 70 fixedly attached thereto. The bracket plate is suitably apertured to receive fastening elements by which the same is fixedly secured to an appropriate portion of the carriage structure 18.

The bracket plate 78 is secured to a portion of the carriage structure 18 which will position the mounting rod 66 in adjacent parallel relation with the take-up roll 22. In such a position, the sleeve 64 is fixedly adjusted to the rod 66 and the collar 60 to the housing 34 so as to position the lower periphery of the friction driven resilient sleeve 58 of the drive mechanism 30 in driving contact with the upper periphery of the take-up roll 22 at a position spaced laterally outwardly from the central portion thereof over which the tubular fabric passes. In this position, the forward peripheral edge of the cutting blade 26 is disposed adjacent the spreader structure 16. In the embodiment shown, the spreader structure 16 is formed with a slot 80 extending upwardly from the lower end thereof within which the cutter blade extends so that a portion of the peripheral cutting edge thereof extends across the fabric passing over the spreader structure 16, so as to effect a cutting action thereof. As best shown in FIG. 3, the upper pormovement will function in operation and is contemplated in the broadest aspects of the present invention.

The limitation on the maximum speed that can be obtained from the attachment as specifically described above is the minimum size of the combined pulley and sleeve assembly. Where it is desired to increase the cutting blade speed beyond that which can be achieved by a minimum size sleeve 58,one modification by which such speed increase can be obtained by changes in the drive mechanism is illustrated in FIG. 4. It will be understood that speed increase can also be obtained by utilizing a transmission assembly with a different gear ratio.

The modified form of driving mechanism for the slitting attachment 12, is generally indicated by the reference numeral 86 in FIG. 4. Since the other component elements of the attachment 12 is shown in FIG. 4 are similar to those previously described the same reference numerals have been applied to corresponding parts. The drive mechanism 86, like the drive mechanism 30, includes a pulley 88 fixedly secured to the drive shaft 48, as before. However, in lieu of the sleeve 58, the drive mechanism 86 includes an endless belt 90 which is trained about the periphery of the pulley 88 and about the outer take-up roll 20. As shown, the belt 90 is a conventional timing belt having grooves or teeth-like formations on the inner periphery thereof and the pulley 88 has its outer periphery configured to mate therewith. The installation for a driving mechanism 86 is somewhat more difficult than that of the drive mechanism 30 in that the former requires the removal of the outer take-up roll 20. In addition, it is necessary to modify the spacers of the inner take-up roll 20 so that the peripheral groove normally provided therein in a position to coincide with the folded edge of the fabric is now positioned to coincide with the belt 90 so as to provide adequate clearance. It will be understood that the provision of fold receiving space in the inner take-up roll 20 is no longer required at the slit fold when slitting is performed in accordance with the procedures of the present invention.

As can be seen from FIG. 4, with this arrangement it is possible to utilize a much smaller sized pulley so as to effect an increase in speed to a desired extent. Also, with respect of FIG. 4 it will be noted that the attachment has been mounted so that the housing 28 is disposed on the opposite side of the spreader portion 16 than is the case with the drive mechanism 30.

FIG. 4 also illustrates a modification in the spreader structure of a knitting machine for accommodating the cutting blade 26 in a manner similar to the slot 80 where the spreader structure of the machine is of a size such that the formation of a slot would seriously impair the strength of the spreader structure. As shown, instead of slotting the structure as previously described, a generally L-shaped rod 92 is suitably fixed to the spreader structure, as by welding or the like, the major leg of the rod extending parallel to the structure so as to provide an effective slot within which the blade 26 extends.

It can be seen that the slitting mechanism attachment 12 operates in conjunction with the operation of the knitting machine 10. The aforesaid rotary movement of the cutting blade provides a particularly effective straight cut in the fabric which is controlled both longitudinally and transversely by the predetermined tensions applied thereto by the take-up rolls 20 and spreader structure 16 as the tubular fabric is progressively knitted on the needle cylinder. This control, both longitudinally and transversely, insures a straight cut which is accomplished by the driven rotary cutter in a continuous clean straight line without snags or the like.

The cutting action is continuous and proceeds at a rate commensurate with the rate of fabric movement through the machine. This rate will vary depending upon the particular machine and the type and style of fabric being knitted and usually would involve operating speeds within a range of from 4 inches per minute to 24 inches per minute.

It will be understood that in the normal operation of the machine with the slitting mechanism attachment l2 operatively associatedtherewith, the slitted fabric is wound up into a roll in the usual fashion by the roll forming mechanism 24 of the machine. In this way, the machine 10, modified in accordance with the principles of the present invention, is normally operable to produce a length of knitted fabric folded lengthwise upon itself and wound up into a roll.

It will be understood that while the attachment 12 described above constitutes the preferred apparatus for carrying out the present method, the method is susceptible to being performed by apparatus of other constructions. For example. any well-known cutting means from fixed blades to driven scissors could be utilized to practice the slitting step of the method. Moreover, while the method of the present invention is particularly applicable to knitting machines of the type and size described above, it will be understood that the present method is also applicable to machines of the stationary needle cylinder type, as well as to machines of smaller size and capacity. While it is greatly preferred to form the longitudinal cut at one of the folds. in its broadest aspects, the present method contemplates the progressive formation of the slit at positions in the tubular fabric other than at a fold thereof.

The present invention serves to facilitate subsequent processing of the fabric and particularly the procedures for producing open width knitted fabric therefrom. In this regard, this is particularly true where the subsequent procedures are carried out in accordance with the teachings of the aforesaid Estes application, the disclosure of which is hereby incorporated by reference into the present specification.

It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiment has been shown and described for the purpose of illustrating the functional and structural principles of this invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

I claim:

1. An attachment for a knitting machine of the type having a spreader structure for receiving thereover a tubular fabric progressively knitted during the operation of said machine to progressively deform the same from an open tubular condition into a flattened transversely elongated condition and cooperating take-up roll means for feeding therebetween the fabric in flattened condition passing from said spreader structure, said attachment comprising a housing, a pair of shafts joumaled in said housing for rotational movement about axes disposed perpendicular to each other, a circular cutting blade fixed to one of said shafts exteriorly of said housing, a pair of gears on said shafts within said housing disposed in meshing relation with respect to one another, a pulley fixed to the other of said shafts exteriorly of said housing, driving means operatively connected with the exterior periphery of said pulley and adapted to be drivingly connected with said takeup roll means for imparting a rotational movement to said pulley in response to the fabric feeding movement of said take-up roll means, and means carried by said housing adapted to mount the same in an operative position on said machine in which (1) said cutting blade is disposed in cooperating relation with said spreader structure to progressively slit the fabric passing thereover along a longitudinally folded edge thereof and (2) said driving means is disposed in the aforesaid drivingly connected relation to said take-up roll means.

2. An attachment as defined in claim 1 wherein said driving means comprises a resilient circular sleeve having an inner periphery fixed to the exterior periphery of said pulley and an outer periphery adapted to be disposed in driving engagement to said take-up roll means periphery laterally outwardly of the fabric passing therethrough when said attachment is disposed in said operative position.

3. An attachment as defined in claim I wherein said driving means includes an endless flexible belt trained about the periphery of said pulley and adapted to be trained about said take-up roll means periphery in a position laterally outwardly of the fabric when said attachment is disposed in said operative position.

4. In a circular knitting machine of the type adapted to progressively form a tubular double knit fabric and having a spreader structure mounted for movement about an axis of rotation operable to receive for rotation therewith and for longitudinal movement thereover the tubular double knit fabric progressively knitted during the operation of the machine and to controllably deform the fabric with a predetermined transverse tension from an open tubular condition into a flattened transversely elongated condition, cooperating take-up rolls mounted for movement about said axis of rotation in synchronism with said spreader structure and for rotational movement about axes parallel with respect to one another for receiving therebetween the fabric in flattened condition passing longitudinally from said spreader structure and for feeding the same longitudinally therethrough so as to apply a predetermined longitudinal tension to the portion of said fabric extending thereto including the portion passing over said spreader structure, and means mounted for movement about said axis of rotation in synchronism with said spreader structure and said take-up rolls for winding up into a roll the fabric in flattened condition fed through said take-up rolls, the improvement which comprises in combination therewith a housing, a pair of shafts journaled in said housing for rotational movement about axes disposed perpendicular to each other, a circular cutting blade fixed to one of said shafts exteriorly of said housing, a pair of gears on said shafts within said housing disposed in meshing relation with respect to one another, a pulley fixed to the other of said shafts exteriorly of said housing, driving means operatively connected with the exterior periphery of said pulley drivingly connected with at least one of said take-up rolls for imparting a rotational movement to said pulley in response to the fabric feeding movement of said take-up rolls, and means carried by said housing mounting the same in an operative position on said machine wherein said cutting blade is disposed in cooperating relation with said spreader structure to progressively slit the fabric passing thereover along a longitudinally folded edge thereof.

5. The improvement as defined in claim 4 wherein said cutting blade includes a peripheral cutting edge having a fabric-engaging cutting edge portion facing in a direction generally opposed to the direction of longitudinal fabric movement, said spreader structure having a longitudinal slot formed in one end thereof adjacent said take-up rolls, said cutting blade being disposed within said slot with said cutting edge portion extending outwardly thereof in transverse relation to the portion of said fabric passing over the one end of said spreader structue defining said slot.

6. The improvement as defined in claim 5 wherein said pulley driving means comprises a resilient circular sleeve having an inner periphery fixed to the periphery of said pulley and an outer periphery disposed in driving engagement to the periphery of one of said take-up rolls laterally outwardly of the fabric.

7. The improvement as defined in claim 5 wherein said pulley driving means includes an endless flexible belt trained about the periphery of said pulley and about the periphery of one of said take-up rolls. 

1. An attachment for a knitting machine of the type having a spreader structure for receiving thereover a tubular fabric progressively knitted during the operation of said machine to progressively deform the same from an open tubular condition into a flattened transversely elongated condition and cooperating take-up roll means for feeding therebetween the fabric in flattened condition passing from said spreader structure, said attachment comprising a housing, a pair of shafts journaled in said housing for rotational movement about axes disposed perpendicular to each other, a circular cutting blade fixed to one of said shafts exteriorly of said housing, a pair of gears on said shafts within said housing disposed in meshing relation with respect to one another, a pulley fixed to the other of said shafts exteriorly of said housing, driving means operatively connected with the exterior periphery of said pulley and adapted to be drivingly connected with said take-up roll means for imparting a rotational movement to said pulley in response to the fabric feeding movement of said take-up roll means, and means carried by said housing adapted to mount the same in an operative position on said machine in which (1) said cutting blade is disposed in cooperating relation with said spreader structure to progressively slit the fabric pAssing thereover along a longitudinally folded edge thereof and (2) said driving means is disposed in the aforesaid drivingly connected relation to said take-up roll means.
 2. An attachment as defined in claim 1 wherein said driving means comprises a resilient circular sleeve having an inner periphery fixed to the exterior periphery of said pulley and an outer periphery adapted to be disposed in driving engagement to said take-up roll means periphery laterally outwardly of the fabric passing therethrough when said attachment is disposed in said operative position.
 3. An attachment as defined in claim 1 wherein said driving means includes an endless flexible belt trained about the periphery of said pulley and adapted to be trained about said take-up roll means periphery in a position laterally outwardly of the fabric when said attachment is disposed in said operative position.
 4. In a circular knitting machine of the type adapted to progressively form a tubular double knit fabric and having a spreader structure mounted for movement about an axis of rotation operable to receive for rotation therewith and for longitudinal movement thereover the tubular double knit fabric progressively knitted during the operation of the machine and to controllably deform the fabric with a predetermined transverse tension from an open tubular condition into a flattened transversely elongated condition, cooperating take-up rolls mounted for movement about said axis of rotation in synchronism with said spreader structure and for rotational movement about axes parallel with respect to one another for receiving therebetween the fabric in flattened condition passing longitudinally from said spreader structure and for feeding the same longitudinally therethrough so as to apply a predetermined longitudinal tension to the portion of said fabric extending thereto including the portion passing over said spreader structure, and means mounted for movement about said axis of rotation in synchronism with said spreader structure and said take-up rolls for winding up into a roll the fabric in flattened condition fed through said take-up rolls, the improvement which comprises in combination therewith a housing, a pair of shafts journaled in said housing for rotational movement about axes disposed perpendicular to each other, a circular cutting blade fixed to one of said shafts exteriorly of said housing, a pair of gears on said shafts within said housing disposed in meshing relation with respect to one another, a pulley fixed to the other of said shafts exteriorly of said housing, driving means operatively connected with the exterior periphery of said pulley drivingly connected with at least one of said take-up rolls for imparting a rotational movement to said pulley in response to the fabric feeding movement of said take-up rolls, and means carried by said housing mounting the same in an operative position on said machine wherein said cutting blade is disposed in cooperating relation with said spreader structure to progressively slit the fabric passing thereover along a longitudinally folded edge thereof.
 5. The improvement as defined in claim 4 wherein said cutting blade includes a peripheral cutting edge having a fabric-engaging cutting edge portion facing in a direction generally opposed to the direction of longitudinal fabric movement, said spreader structure having a longitudinal slot formed in one end thereof adjacent said take-up rolls, said cutting blade being disposed within said slot with said cutting edge portion extending outwardly thereof in transverse relation to the portion of said fabric passing over the one end of said spreader structue defining said slot.
 6. The improvement as defined in claim 5 wherein said pulley driving means comprises a resilient circular sleeve having an inner periphery fixed to the periphery of said pulley and an outer periphery disposed in driving engagement to the periphery of one of said take-up rolls laterally outwardly of the fabric.
 7. The Improvement as defined in claim 5 wherein said pulley driving means includes an endless flexible belt trained about the periphery of said pulley and about the periphery of one of said take-up rolls. 